Process for recovery of escaping aromas of food, &amp;c.



C. W. TRIGG.

PROCESS FOR RECOVERY OF ESCAPI NG AROMAS OF FOOD, 62c.

APPLICATION FILED NOV-19, 1917- 1,367,725. Patented Feb. 8, 1921.

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awwmtoz 7 UNITED STATES PATENT oFI- cai cnmnns w. TRIGG, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR To .form E. KING, or nn'rnorr, MICHIGAN. I

PROCESS non RECOVERY or nscnnN nnoims or noon, ac.

Application fil ed November 19, 1917. Serial No.

To allwkomz'tmay concern:

Be it known that I, CHARLES W. Truce, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny, State. of Pennsylvania, have invented a new and useful Improvement in Processes for Recovery of Escaping Aromas of Food, &c., of which the following is aspeeification.

This process relates to the recovery of the volatile, aromatic and flavoring substances escaping during the preparation of solutions .and extracts of food or of dried, dehydrated,

it is the purpose of this discovery to apply a this process of recovery.

Cafi'eol is a complex compound Whose chemical constitutents no one has ever determined with technical accuracy, but the term has often been given a formula which for some purposes may be accurate enough. I use it in-thisspecification and claims in the sense of the aroma and flavoring substances that give the coffee beverage its pleasing odor and flavor. These aromas are veffy often spoken of as the essential oils of co ee The prior art shows many attempts to prepare cofi'ee extracts, by steam distillation, destructive distillation, mere evapor-i zation, repeated infusions with cold Water to extract the aromas before extracting the other substances and evaporating to dryness, absorption of the aromas in an absorbing medium and adding the absorbing medium and the absorbed substance to the coffee extract where both remain, subjecting the ground coffee-berries to the action of certain solvents and many other processes. So far as I am informed none of these processes has met with any, or at least any considerable, commercial success.

\ Specification of Letters Patent.

Patented Feb. 8, 1921. 202,764.

Cafi'eol is a very volitant and fugitive constituent and in many of the processes very little, if any of. it, is recovered. In

other of the processes, the processes are such as to cause chemical reactions that make it impossible for the final coffee extract to duplicate. the original beverage when in water solution.

It is the object of-this discovery to effect the recovery of this fugacious cafl'eol in large quantities wherever it escapes and to' make this recovery and add it to the dry extract under such conditions as to' neither change the chemical nature of the constituents of the dry extract nor the caffeol, thus making possible the substantial attainment of coffee beverage from water-soluble coffee extract with identical properties to coffee beverage made from fresh ground roasted coffee.

To better illustrate and visually summarize my process, I have attached a sheet of drawing or flow sheet,

In extracting the cofl'ee infusion by evaporation by spraying in a vacuum some of the cafi'eol is carried down with the condensation of thevapors in what I call and illustrate inthe flow sheet as a trap. The recovery of the cafi'eol by this distillation,

and a suitable solvent, I have madethe subject of a separate application and hence I will not here further detail the process.

But it will be noted that the trap is con nected up with a vacuum pump in the drawings and that some of the cafleol is shown passing intothe pump. This is inevitable and ordinarily. this caffeol would be lost. Upon passing through the pump the caffeol together with the exhausting air passes into a slack tank, from thence through an air compressor .into an autoclave. The slack tank should be capable of withstanding a high vacuum or several hundred pounds pressure and its purpose is to prevent too high a pressure accumulating between the vacuum pump and the compressor in case the compressor at times does not take the aromatized air as fast as the suction pump delivers it; or to prevent injury to the vacuum pum in case the compression pump is exhibiting a greater temporary capacity than the vacuum pump.

It is also to be noted that the aromas or caffeol escaping from the roasting coffee, from the coffee cooling on the trays, from the evaporization of a solvent to leave caffein, and there are perhaps several other operations in connection with cofiee where my process could be advantage0usly used.

From the compressor the aromatized air and vapors pass intothe absorption autoclave in which is introduced a suitable viscous, aqueous, or volatile solvent, such as water, pentane, ethyl ether, butane, ethyl chlorid, methyl chlorid, etc. The aromatized air and vapor under pressure is bubbled through the solvent or passed through 'a spray ofthe solvent. The interior pressure in the autoclave can be maintained-constant at a pressure preferably between 200- 250 pounds to the square inch by means of a safety valve of the Fisher type or a spring safety valve, for instance. This safety valve is calculated to let the de-aromatized gases escape at the same rate that the aromabearing gases are pumped in and willbe a substantially continuous operation.

The caffeol when under heavy pressure is much more susceptible to the action of the solvent and especially so when the contents of the autoclave are refrigerated. This refrigeration can be secured by passing the escaping, de-aromatized vapors and air through a coil in the refrigerating brine or solution. The heat absorbed by the expanding gases cools the brine. v A

From the autoclave the solvent and cafieol can be led to a tank called the impregnator, wherein the dry soluble coffee extract from which the cafieol has escaped and the solvent bearing the cafi'eol may be united preferably under pressure. The solvent may be then driven off by allowing the pressure to return to normal, exerting a slight vacuum, permitting the temperature to return to atmospheric, or by applying a small amount of heat. The less rapid volatibi'lity of the cafieol as Well as the afinity of the dry extract. for the cafieol will avoid the escape of the cafioel during the evaporation of t solvent.

The evaporating solvent may be con-' densed as indicated ,in the drawing and returned for storage and re-use.

The impregnated extract may be pressed into tablets which preferably are coated with some water-soluble, physiologically inactive, neutral, non-deliquescent, material such as gelatin, albumen, casein, algin, etc., or combination thereof; or the dry finished product may be marketed in capsules of gelatin or other suitable material. The

' tablets may be prepared for the market in "suitable air-tight packages. the impregnated extract into tablets and In pressing even .in packing the tablets, it is advantamamas geous to do the same in an atmosphere havmg a supernormal pressure to prevent the volatile cafi'eol escaping.

The left hand side of the flow sheet also depicts'a .process which is made the subject of a separate application; This process consists of extracting the ground coffee by separating the aqueous layer from the solvent and cafieol. This solvent may, then be placed in the absorption autoclave, where under pressure and refrigeration it will be -capable. of absorbing or dissolving. more cafieol. This process of condensation, however, does not catch all the cafieol and hence it is here where my present process claimed in this application, may attach. The cafieol passing through the vacuum pum isthen recovered by the agencies already escribed.

It is well to add that it 'is preferable not to use a vacuum pump of the liquid seal variety. as this is liable to contaminate and absorb the gases passing through'it.

What ll, claim is:

l. The process for the purpose specified,

comprising the steps of pumping of a gas bearing cofi'ee aroma into. a closed chamber, the maintaining of the contents of said chamber at a super-atmospheric pressure, and the passing of the gas with such cofi'ee aroma under such pressure into contact with a solvent of said cofi'ee aroma.

, 2. The process for the purpose specified, comprising the steps of pumping of a gas bearing a cofiee aroma into a closed receptacle, the maintaining of the receptacle in a chilled condition, the maintaining of a super-atmospheric pressure for the contents of the receptacle, and the assing of the gas bearing thecofi'ee aroma 1nto contact with a cofiee aroma solvent.

3. The process for the purpose specified, comprising the steps of pumping of gas containing cofiee aroma into a closed receptacle, the maintaining of a super-atmospheric pressure in said receptacle, the pass-. ing of the gas bearin the aroma under pressure into contact with a cafieol solvent and allowing the dearomatized gas to escape and the guiding of the expanding gas in proximity with the closed receptacle to chill the contents thereof. I

4:. Theprocess for the purpose specified, comprising the steps of pumping of gas bearing cofi'ee aroma into a closed receptacle, the maintaining of the contents of the receptacle under super-atmospheric pressure,

the passing of the gas bearing the cofiee vent, and the passing of the solvent contaming the coifee'aroma into a chamber whose contents are under pressure and into contact with cofiee extract to impregnate the same with coffee aroma.

5. The process for the purpose specified,

. comprising the steps of pumping of gas containing coffee aroma into a closed receptacle, the maintaining of a super-atmospheric pressure for the contents of said receptacle, the'passing of the gas bearing the coffee aroma into contact with the coffee aroma solvent, the passing of the solvent bearing the coffee aroma into a chamber whose contents are under pressure and which contains 'cofiee-extract, the said solvent and cafi'col condensing of the vapors arising during evaporation and the extraction of the caffeol therefrom, the exhausting of the vacuum chamber and compressing of the contents pumped therefrom in a closed chamber ,under relatively heavy pressure,

and the passing of the gases bearing the coffee aroma into contact with the caifeol solvent in said closed chamber.

7. The process for the purpose specified,

comprising the steps of evaporation of acofleeinfusion in a vacuum chamber, the condensing of the vapors therefrom and extracting the same for caffeol, the exhausting of said chamberand leading the gases pumped therefrom into a slack tank, the

compressing of the gases drawn from the I slack tank into a closed chamber where the pressure is maintained at a relatively high degree, and the passing of the gases thus obtained bearing; the aroma through a cafi'eol solvent.

In witness whereof, I have hereunto set my hand on the 10thda ofNovember, 1917.

CH'A LES W. TRIGG. 

